chemistry
posted by Amandeep .
What am I doing wrong?
If a current of 54 A flows into a cell for 45 minutes 30 s, determine the mass of chronium deposited.
My answer:
54 x 2730 s = 147420
147430/96485
= 1.52 mols
m = n x M
=1.52 x 52
= 79.5

chemistry 
DrBob222
I get 1.528 which would round to 1.53 but it won't make that much difference. I think your problem is the molar mass of Cr. 1 F (96,485 coulombs) will deposit 1 equivalent of Cr and 1 eq is molar mas of 52 divided by change in number of electrons. The problem isn't really specific about the nature of the Cr in solution (or perhaps you just didn't include it in your post); however, most electroplated Cr, I think, comes from Cr^+3 in solution. So the change in electrons will be 3 and 06,485 coulombs will deposit 52/3 = ?? grams Cr.

chemistry 
Amandeep
Will this help?
A car bumper is plated with chronium using chronium(III)ions in solution. If a current of 54 A flows into a cell for 45 minutes 30 s, determine the mass of chronium deposited. 
chemistry 
DrBob222
Yes. It is Cr^+3 in solution and the half cell is Cr^+3 + 3e ==> Cr.
So the equivalent weight is what I posted in my first response of 52/3 or a little over 17 g for 96,485 coulombs. I get something like 26 grams but that's an estimate.
Respond to this Question
Similar Questions

chemistry
A car bumper is plated with chromium using chromium(III) ions in solution. If a current of 54 A flows in the cell for 45 min 30 s, determine the mass of chronium deposited on the bumper. 
chemistry
The electrochemical cell described by the cell notation has an Eo of 0.37 V. Calculate the maximum electrical work (kJ) the cell has done if 331.73 g of Cu(s) (Molar Mass  63.55 g/mol) reacts. Round your answer to 3 significant figures. … 
chemistry
The electrochemical cell described by the cell notation has an Eo of 0.37 V. Calculate the maximum electrical work (kJ) the cell has done if 331.73 g of Cu(s) (Molar Mass  63.55 g/mol) reacts. Round your answer to 3 significant figures. … 
chemistry
The electrochemical cell described by the cell notation has an Eo of 0.37 V. Calculate the maximum electrical work (kJ) the cell has done if 331.73 g of Cu(s) (Molar Mass  63.55 g/mol) reacts. Round your answer to 3 significant figures. … 
chemistry
The electrochemical cell described by the cell notation has an Eo of 0.37 V. Calculate the maximum electrical work (kJ) the cell has done if 331.73 g of Cu(s) (Molar Mass  63.55 g/mol) reacts. Round your answer to 3 significant figures. … 
Chemistry
A solution of H2SO4 was electrolyzed using the inert platinum electrodes. A) Write the balanced halfreactions for the anode and cathode in this cell. B) How many coulombs passed through the cell in 90 minutes at 8.0 amperes? 
Chemistry
A current of 2.34 A is delivered to an electrolytic cell for 85 minutes. How many grams of Au will be deposited from an aqueous solution of AuCl3? 
Chemistry
A current of 2.34 A is delivered to an electrolytic cell for 85 minutes. How many grams of Au will be deposited from an aqueous solution of AuCl3? 
Chemistry
Two electrolysis cells are set up in series so that the same current flows through each. In one compartment 5.40 g of Ag (molar mass = 108 g/mol) is deposited from a Ag+ solution. What mass of Cu (molar mass = 64 g/mol) is deposited … 
Chemistry
Determine the mass of chlorine produced when 200A of current flows for 24 hours through a cell of molten NaCl.